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Related papers: Extragalactic H2 and its variable relation to CO

200 papers

Photon initiated chemistry, \textit{i.e.} the interaction of light with chemical species, is a key factor in the evolution of the atmosphere of exoplanets. For planets orbiting stars in UV-rich environments, photodissociation induced by…

Chemical Physics · Physics 2022-07-06 Marco Pezzella , Jonathan Tennyson , Sergei N. Yurchenko

It has been proposed that the mass-metallicity relation of galaxies exhibits a secondary dependence on star formation rate (SFR), and that the resulting M-Z-SFR relation may be redshift-invariant, i.e., "fundamental." However, conflicting…

Astrophysics of Galaxies · Physics 2014-12-23 Samir Salim , Janice C. Lee , Chun Ly , Jarle Brinchmann , Romeel Davé , Mark Dickinson , John J. Salzer , Stéphane Charlot

The metallicity and gas density dependence of interstellar depletions, the dust-to-gas (D/G), and dust-to-metal (D/M) ratios have important implications for how accurately we can trace the chemical enrichment of the universe; either by…

We investigated optical absorption coefficient spectra of an epitaxial VO2 film in wide photon energy (0.5 - 5.0 eV) and temperature (100 - 380 K) regions. In its insulating phase, we observed two d-d transition peaks around 1.3 eV and 2.7…

Strongly Correlated Electrons · Physics 2007-05-23 C. H. Koo , J. S. Lee , M. W. Kim , Y. J. Chang , T. W. Noh , J. H. Jung B. G. Chae , H. -T. Kim

We present a study of the chemical abundances of Solar neighbourhood stars associated to dynamical structures in the Milky Way's (thick) disk. These stars were identified as overdensity in the eccentricity range 0.3< ecc < 0.5 in the…

Astrophysics of Galaxies · Physics 2015-06-22 Amina Helmi , Mary Williams , K. C. Freeman , J. Bland-Hawthorn , G. De Silva

The CO-to-H$_2$ conversion factor ($X_\mathrm{CO}$) is known to correlate with the metallicity ($Z$). The dust abundance, which is related to the metallicity, is responsible for this correlation through dust shielding of dissociating…

Astrophysics of Galaxies · Physics 2017-01-25 Hiroyuki Hirashita , Nanase Harada

Context: Galaxy metallicities have been measured to redshift z~2 by gas-phase oxygen abundances of the interstellar medium using the R23 and N2 methods. Galaxy stellar metallicities provide crucial data for chemical evolution models but…

The Kennicutt-Schmidt (K--S) law in IC 342 is examined using the 12CO-to-H2 conversion factor (Xco,v), which depends on the metallicity and CO intensity. Additionally, an optically thin 13CO (1-0) is also independently used to analyze the…

Astrophysics of Galaxies · Physics 2015-06-17 Hsi-An Pan , Nario Kuno , Akihiko Hirota

We present the mass-metallicity (MZ) and luminosity-metallicity (LZ) relations at z ~ 0.8 from ~1350 galaxies in the Deep Extragalactic Evolutionary Probe 2 (DEEP2) survey. We determine stellar masses by fitting the spectral energy…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 H. J. Zahid , L. J. Kewley , F. Bresolin

We present new calibrations of the widely used H_alpha, [OII], and UV luminosity vs. star formation rate (SFR) relations. Using our evolutionary synthesis code GALEV we compute the different calibrations for 5 metallicities, from 1/50 solar…

Astrophysics · Physics 2009-11-11 Jens Bicker , Uta Fritze -- v. Alvensleben

The presence of asymmetries and substructures in protoplanetary disks, revealed by both dust and gas emission, highlights the potential interplay and the broader connection between chemistry and dynamics in disk evolution. We explore…

Experimental measurements and theoretical calculations of state-to-state rate coefficients for rotational energy transfer of CO in collision with H$_2$ are reported at the very low temperatures prevailing in dense interstellar clouds (5 -…

We present numerical computations and analytic scaling relations for interstellar ion-molecule gas phase chemistry down to very low metallicities ($ 10^{-3} \times$ solar), and/or up to high driving ionization rates. Relevant environments…

Astrophysics of Galaxies · Physics 2015-09-09 Shmuel Bialy , Amiel Sternberg

The formation and evolution of galaxies is imprinted on their stellar population radial gradients. Two recent articles present conflicting results concerning the mass dependence of the metallicity gradients for early-type dwarf galaxies. On…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-11 M. Koleva , Ph. Prugniel , S. De Rijcke , W. W. Zeilinger , D. Michielsen

Nearby spiral galaxies show an extremely tight correlation between tracers of molecular hydrogen (H_2) in the interstellar medium (ISM) and tracers of recent star formation, but it is unclear whether this correlation is fundamental or…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Mark R. Krumholz , Adam K. Leroy , Christopher F. McKee

We study how the cosmic environment affects galaxy evolution in the Universe by comparing the metallicities of dwarf galaxies in voids with dwarf galaxies in more dense regions. Ratios of the fluxes of emission lines, particularly those of…

Astrophysics of Galaxies · Physics 2017-02-03 Kelly A. Douglass , Michael S. Vogeley

We report results from a FUSE survey of interstellar molecular hydrogen (H2) in the Galactic disk toward 139 O-type and early B-type stars at Galactic latitudes $|b| < 10^{\circ}$, with updated photometric and parallax distances. The H2…

Astrophysics of Galaxies · Physics 2021-04-21 J. Michael Shull , Charles W. Danforth , Katherine L. Anderson

We investigated the magnetic field (H)-dependent optical conductivity spectra of MgB2 thin film in the far-infrared region. The H-dependences can be explained by the increase of normal metallic regions embedded in the superconducting…

Strongly Correlated Electrons · Physics 2009-11-07 H. J. Lee , J. H. Jung , K. W. Kim , M. W. Kim , T. W. Noh , Y. J. Wang , W. N. Kang , Eun-Mi Choi , Hyeong-Jin Kim , Sung-Ik Lee

The low metallicity interstellar medium of dwarf galaxies gives a different picture in the far infrared(FIR)/submillimetre(submm)wavelengths than the more metal-rich galaxies. Excess emission is often found in the submm beginning at or…

We report results of specific heat measurements on polycrystalline samples of the layered superconductor, Na(0.3)CoO(2).1.3H(2)O. The electronic contribution to the specific heat, gamma, is found to be 12.2 mJ/mol-K2. The feature at the…

Superconductivity · Physics 2015-06-24 B. G. Ueland , P. Schiffer , R. E. Schaak , M. L. Foo , V. L. Miller , R. J. Cava